package com.skillworld.webapp.web.pages.rest.school;

import org.apache.tapestry5.annotations.ContentType;
import org.apache.tapestry5.annotations.Property;
import org.apache.tapestry5.annotations.SessionState;
import org.apache.tapestry5.ioc.annotations.Inject;
import org.apache.tapestry5.services.Request;

import com.skillworld.webapp.model.courseservice.AlreadyAnStudentException;
import com.skillworld.webapp.model.courseservice.CourseService;
import com.skillworld.webapp.model.courseservice.NoVacanciesLeftException;
import com.skillworld.webapp.model.util.PermissionDeniedException;
import com.skillworld.webapp.web.util.ErrorMessages;
import com.skillworld.webapp.web.util.UserSession;

import es.udc.pojo.modelutil.exceptions.InstanceNotFoundException;

@ContentType("text/xml")
public class ApplyCourse {
	
	@SuppressWarnings("unused")
    @Property
    private String errorMessage = null;
    
    @Inject
    private CourseService courseService;
    
    @SessionState(create=false)
    private UserSession userSession;
   
    private boolean userSessionExists;
    
    @Inject
    private Request request;
   

    void onPassivate() 
    {
        return;
    }
    
    void onActivate()
    {       
        if (!userSessionExists)
        {
            errorMessage = ErrorMessages.NOT_LOGGED_IN;
            return;
        }
        
        String courseParam = request.getParameter("course");
        
        if (courseParam == null)
        { 
            errorMessage = ErrorMessages.INVALID_ARGUMENTS;
            return;
        }
 
        
        try
        {
        	long courseId = Long.parseLong(courseParam);
        	courseService.applyCourse(courseId, userSession.getUserId()); 
        }
        catch (InstanceNotFoundException e)
        { errorMessage = ErrorMessages.INSTANCE_NOT_FOUND; }
        catch (PermissionDeniedException e)
        { errorMessage = ErrorMessages.PERMISSION_DENIED; }
        catch (AlreadyAnStudentException e)
        { errorMessage = ErrorMessages.ALREADY_IN_COURSE; }  
        catch (NoVacanciesLeftException e) 
        { errorMessage = ErrorMessages.NO_VACANCIES_LEFT; }        
    }  
}
